Methods of plasma dicing bulk acoustic wave components

ABSTRACT

Aspects of this disclosure relate to methods of manufacturing bulk acoustic wave components. Such methods include plasma dicing to singulate individual bulk acoustic wave components. A buffer layer can be formed over a substrate of bulk acoustic wave components such that streets are exposed. The bulk acoustic wave components can be plasma diced along the exposed streets to thereby singulate the bulk acoustic wave components

CROSS REFERENCE TO PRIORITY APPLICATION

This application claims the benefit of priority of U.S. ProvisionalPatent Application No. 62/747,486, filed Oct. 18, 2018 and titled “BULKACOUSTIC WAVE COMPONENTS AND METHODS OF PLASMA DICING THE SAME,” thedisclosure of which is hereby incorporated by reference in its entiretyherein.

BACKGROUND Technical Field

Embodiments of this disclosure relate to acoustic wave components and,more specifically, to bulk acoustic wave components.

Description of Related Technology

Acoustic wave filters can be implemented in radio frequency electronicsystems. For instance, filters in a radio frequency front end of amobile phone can include acoustic wave filters. An acoustic wave filtercan filter a radio frequency signal. An acoustic wave filter can be aband pass filter. A plurality of acoustic wave filters can be arrangedas a multiplexer. For example, two acoustic wave filters can be arrangedas a duplexer.

An acoustic wave filter can include a plurality of acoustic waveresonators arranged to filter a radio frequency signal. Example acousticwave filters include surface acoustic wave (SAW) filters and bulkacoustic wave (BAW) filters. BAW filters include BAW resonators. ExampleBAW resonators include film bulk acoustic wave resonators (FBARs) andsolidly mounted resonators (SMRs). In BAW resonators, acoustic wavespropagate in a bulk of a piezoelectric layer.

BAW components can include packaged BAW resonators enclosed within asealed portion. Packaging structures add to the size of the BAWcomponent. There is a desire for reducing the size of BAW componentswithout sacrificing reliability and performance.

SUMMARY OF CERTAIN INVENTIVE ASPECTS

The innovations described in the claims each have several aspects, nosingle one of which is solely responsible for its desirable attributes.Without limiting the scope of the claims, some prominent features ofthis disclosure will now be briefly described.

One aspect of this disclosure is a method of manufacturing singulatedbulk acoustic wave components. The method includes forming a bufferlayer over a substrate of an array of bulk acoustic wave components soas to form exposed streets between individual bulk acoustic wavecomponents. The method also includes plasma dicing the bulk acousticwave components along the exposed streets to thereby singulate the bulkacoustic wave components.

Each of the singulated bulk acoustic wave components can include a bulkacoustic wave resonator and a cap enclosing the bulk acoustic waveresonator. The cap can include a sidewall that is 5 microns or less froman edge of the substrate of the respective singulated bulk acoustic wavecomponent. The sidewall can be at least 1 micron from the edge of therespective singulated bulk acoustic wave component. The sidewall caninclude copper.

The plasma dicing can include etching through both the substrate and acap substrate. The bulk acoustic wave component can include a bulkacoustic wave resonator located over the substrate and under the capsubstrate. The substrate and the cap substrate can be siliconsubstrates.

The method can further include forming a conductor over the substrate.The conductor can extend laterally from a via that extends through thesubstrate. The conductor can be electrically connected to a conductivelayer in the via. Forming the buffer layer can be performed such thatthe buffer layer is over at least a portion of the conductor. The methodcan further include forming solder over the conductor such that thesolder is non-overlapping with the via.

The substrate can be a silicon substrate. The buffer layer can be amaterial that etches at least 30 times slower than silicon during theplasma dicing. The buffer layer can include a resin. Forming the bufferlayer can include forming the exposed streets by way of aphotolithographic process.

The bulk acoustic wave components can each include a film bulk acousticwave resonator.

Another aspect of this disclosure is a method of manufacturing bulkacoustic wave components. The method includes providing a first waferbonded with a second wafer. The first wafer has bulk acoustic resonatorsthereon. The second wafer is over and spaced apart from the bulkacoustic resonators. The method includes forming a buffer layer on aside of the first wafer that is opposite to the bulk acoustic waveresonators such that streets are exposed. The method includes plasmadicing through the first wafer and the second wafer along the exposedstreets to form singulated bulk acoustic wave components.

The first wafer and the second wafer can be silicon wafers.

Each of the singulated bulk acoustic wave components can include a bulkacoustic wave resonator of the bulk acoustic wave resonators and a capenclosing the bulk acoustic wave resonator. The cap can include asidewall. The sidewall can be in a range from 1 micron to 5 microns awayfrom an edge of a substrate of the respective singulated bulk acousticwave component, in which the substrate corresponds to a portion of thefirst wafer prior to plasma dicing.

Another aspect of this disclosure is a method of manufacturing bulkacoustic wave components. The method includes forming a buffer layerover a silicon substrate of bulk acoustic wave components such thatstreets are exposed. The method also includes plasma dicing the bulkacoustic wave components along the exposed streets to thereby singulatethe bulk acoustic wave components. The singulated bulk acoustic wavecomponents each include a bulk acoustic wave resonator and a capenclosing the bulk acoustic wave resonator. The cap includes a siliconcap substrate and a sidewall that is spaced apart from an edge of thesilicon substrate of the respective singulated bulk acoustic wavecomponent by a distance in a range from 1 micron to 5 microns.

The sidewall can include copper. The he buffer layer can include aresin. The bulk acoustic wave resonator can be a film bulk acoustic waveresonator.

Another aspect of this disclosure is a bulk acoustic wave component thatincludes a substrate, at least one bulk acoustic wave resonator on thesubstrate, and a cap enclosing the at least one bulk acoustic waveresonator. The cap includes a sidewall spaced apart from an edge of thesubstrate. The sidewall is 5 microns or less from the edge of thesubstrate.

The sidewall can be 3 microns or less from the edge of the substrate.The sidewall can be at least 1 micron from the edge of the substrate.

The bulk acoustic wave component can further include a via extendingthrough the substrate, a conductive layer in the via, and a buffer layerin the via.

The bulk acoustic wave component can further include a via extendingthrough the substrate, a conductor extending laterally from the via andelectrically connected with conductive layer in the via, and solder onthe conductor and located laterally from the via.

The at least one bulk acoustic wave resonator can include a film bulkacoustic wave resonator. The at least one bulk acoustic wave resonatorcan include a solidly mounted resonator.

The substrate can be a silicon substrate. A top portion of the cap caninclude a silicon cap substrate.

The sidewall can include copper.

The at least one bulk acoustic wave resonator can include a plurality ofbulk acoustic wave resonators included in a filter arranged to filter aradio frequency signal. The plurality of bulk acoustic wave resonatorscan include at least 10 bulk acoustic wave resonators.

Another aspect of this disclosure is a bulk acoustic wave component thatincludes a silicon substrate, at least one bulk acoustic wave resonatoron the silicon substrate, and a cap enclosing the at least one bulkacoustic wave resonator. The cap includes a cap substrate and asidewall. The cap substrate includes silicon. The sidewall is spacedapart from an edge of the silicon substrate by a distance in a rangefrom 1 micron to 5 microns.

The bulk acoustic wave component can further include a via extendingthrough the silicon substrate, a conductive layer in the via, and abuffer layer in the via.

The bulk acoustic wave component can further include a via extendingthrough the substrate, a conductor extending laterally from the via andelectrically connected with conductive layer in the via, and solder onthe conductor and located laterally from the via.

The sidewall can include copper. The at least one bulk acoustic waveresonator can include at least 10 bulk acoustic wave resonators includedin an acoustic wave filter arranged to filter a radio frequency signal.

Another aspect of this disclosure is a wireless communication devicethat includes an antenna and a bulk acoustic wave component. The bulkacoustic wave component includes a substrate, bulk acoustic waveresonators on the substrate, and a cap enclosing the bulk acoustic waveresonators. The cap includes a sidewall that is spaced apart from anedge of the substrate by 5 microns or less. The bulk acoustic waveresonators is included in a filter in communication with the antenna.

The wireless communication device can be a mobile phone.

The wireless communication device can further include a radio frequencyamplifier in communication with the filter and a switch coupled betweenthe filter and the antenna.

For purposes of summarizing the disclosure, certain aspects, advantagesand novel features of the innovations have been described herein. It isto be understood that not necessarily all such advantages may beachieved in accordance with any particular embodiment. Thus, theinnovations may be embodied or carried out in a manner that achieves oroptimizes one advantage or group of advantages as taught herein withoutnecessarily achieving other advantages as may be taught or suggestedherein.

The present disclosure relates to U.S. patent application Ser. No.16/599,032, titled “BULK ACOUSTIC WAVE COMPONENTS,” filed on even dateherewith, the entire disclosure of which is hereby incorporated byreference herein.

BRIEF DESCRIPTION OF THE DRAWINGS

Embodiments of this disclosure will now be described, by way ofnon-limiting example, with reference to the accompanying drawings.

FIG. 1 is a flow diagram of an example process of manufacturing bulkacoustic wave components according to an embodiment.

FIGS. 2A to 2E are a cross sectional views illustrating a process ofmanufacturing of bulk acoustic wave components according to anembodiment.

FIG. 3A is a cross sectional diagram of a bulk acoustic wave componentaccording to an embodiment.

FIG. 3B is a cross sectional diagram of a bulk acoustic wave componentaccording to another embodiment.

FIG. 4 is a schematic diagram of a transmit filter that includes bulkacoustic wave resonators of a bulk acoustic wave component according toan embodiment.

FIG. 5 is a schematic diagram of a receive filter that includes bulkacoustic wave resonators of a bulk acoustic wave component according toan embodiment.

FIG. 6 is a schematic diagram of a radio frequency system that includesa bulk acoustic wave component according to an embodiment.

FIG. 7 is a schematic diagram of a radio frequency module that includesa bulk acoustic wave component according to an embodiment.

FIG. 8 is a schematic diagram of a radio frequency module that includesa bulk acoustic wave component according to an embodiment.

FIG. 9A is a schematic block diagram of a wireless communication devicethat includes a filter in accordance with one or more embodiments.

FIG. 9B is a schematic block diagram of another wireless communicationdevice that includes a filter in accordance with one or moreembodiments.

DETAILED DESCRIPTION OF CERTAIN EMBODIMENTS

The following description of certain embodiments presents variousdescriptions of specific embodiments. However, the innovations describedherein can be embodied in a multitude of different ways, for example, asdefined and covered by the claims. In this description, reference ismade to the drawings where like reference numerals can indicateidentical or functionally similar elements. It will be understood thatelements illustrated in the figures are not necessarily drawn to scale.Moreover, it will be understood that certain embodiments can includemore elements than illustrated in a drawing and/or a subset of theelements illustrated in a drawing. Further, some embodiments canincorporate any suitable combination of features from two or moredrawings.

Acoustic wave filters can filter radio frequency (RF) signals in avariety of applications, such as in an RF front end of a mobile phone.An acoustic wave filter can include a bulk acoustic wave (BAW)component. The BAW component can include a single die. The BAW componentcan include one or more BAW resonators on a substrate, such as a siliconsubstrate. The one or more BAW resonators can be enclosed by a cap ofthe BAW component. The cap can include another silicon substrate andsidewalls. The cap can form a hermetic seal around the one or more BAWresonators. The sidewalls can include copper, for example.

BAW components can be manufactured by dicing bonded wafers with a hollowportion between the wafers. Chipping has occurred in a portion of a BAWcomponent facing the hollow portion. When there is a relatively bigchip, a hermetic seal around BAW resonators can be broken. To reduceand/or eliminate the risk of chipping, BAW components can include aspace between an edge of the BAW component and the sealed portion. Thespace can be, for example, about 15 to 20 microns from a sidewall of acap to a diced edge of a BAW component. The space can consume area ofBAW components.

Aspects of this disclosure relate to a plasma dicing method for bulkacoustic wave components. A buffer layer can be formed over bulkacoustic wave components to cover a re-wiring layer. The buffer layercan be formed such that streets for dicing are exposed. The buffer layercan serve as a masking layer for plasma dicing. BAW components can besingulated by plasma dicing. Plasma dicing can result in less chippingof BAW components relative to other dicing techniques, such as bladedicing or laser dicing. With plasma dicing, a sidewall of a capenclosing one or more BAW resonators can be closer to a diced edge ofthe BAW component than for other dicing techniques without increasingchipping risk for BAW components. The plasma dicing can involve dicingthrough an upper wafer and a lower wafer across a hollow portion. Theupper wafer and the lower wafer can be silicon wafers.

With plasma dicing, the size of BAW components can be reduced. With lessspace between a sidewall of a cap and an edge of a BAW component, moreBAW components can be included on a wafer. Moreover, the BAW componentscan consume less area in modules.

Blade dicing techniques typically dice sharp edges and there can be sidestress in blade dicing a chip. This can result in cracking and/orchipping at a sharp edge of a blade diced component. With plasma dicing,a pattern can be made with a photolithographic process for dicing andthere can be no significant mechanical side stress during plasma dicing.Accordingly, a sharp edge can be maintained with plasma dicing whilereducing and/or eliminating damage that can result from mechanicalbreaking. In certain instances, plasma dicing can result in corners of aBAW component that are more rounded with more reliable performancecompared to mechanical breaking techniques. Rounded corners can reduceand/or eliminate the risk of BAW components cracking and/or chipping.

Using manufacturing techniques disclosed herein, the yield of BAWcomponents from a single wafer can be improved by about 10% to 18%relative to a previous manufacturing method in certain instances. Theimprovement in yield can reduce manufacturing costs. Manufacturing costscan be reduced even if there is an increase in costs as a result ofadditional processing operations and/or facility investment, due to theimproved yield.

Methods of manufacturing BAW components with plasma dicing aredisclosed. FIG. 1 is a flow diagram of an example process 10 ofmanufacturing bulk acoustic wave components according to an embodiment.The process 10 will be described with reference to cross sectional viewsillustrated in FIGS. 2A to 2E. Any of the methods discussed herein mayinclude more or fewer operations and the operations may be performed inany order, as appropriate.

The process 10 includes providing a substrate with one or more BAWresonators enclosed within a cap at block 12. The substrate can be asilicon substrate. The cap can include sidewalls and a second substratethat together enclose the one or more BAW resonators. The secondsubstrate can be a silicon substrate. The one or more BAW resonators caninclude a film bulk acoustic wave resonator (FBAR) and/or a solidlymounted resonator (SMR).

A re-wiring layer is formed over the substrate at block 14. There-wiring layer includes a conductor that extends laterally from athrough substrate via. The re-wiring layer can be referred to as awiring layer. The re-wiring layer can be formed during the sameprocessing operation(s) as forming a conductive layer in one or morethough substrate vias of a BAW component. The re-wiring layer and theconductive layer can be around 5 microns thick, for example. Solder canbe formed over a portion of the re-wiring layer. The re-wiring layer canprovide an electrical connection from the conductive layer in a thoughsubstrate via to solder of the BAW component. With the re-wiring layer,solder can be formed over any suitable part of a substrate. Forinstance, the solder can be formed laterally from a through substratevia. The solder and the through substrate via are non-overlapping incertain instances.

FIG. 2A illustrates a cross section of a plurality of BAW componentswith the re-wiring layer that is formed at block 14 of the process 10.As illustrated in FIG. 2A, the plurality of BAW components have not yethave been singulated. FIG. 2A illustrates a cap substrate 21, asubstrate 22, sidewalls 23, BAW resonators 24, air cavities 25, throughsubstrate vias 26, a conductive layer 27 in respective though substratevias 26, a re-wiring layer 28, and electrodes 29. Before individual BAWcomponents are singulated, a first wafer includes the substrate 22 ofeach of the individual BAW components and a second wafer includes thecap substrate 21 of each of the individual BAW components. Asillustrated, the first wafer is bonded to the second wafer.

The BAW resonators 24 are enclosed within a cap that includes the capsubstrate 21 and sidewalls 23. The BAW resonators 24 are enclosed withinthe cap before the re-wiring layer 28 is formed. As illustrated, abonding layer 30 and a cap layer 31 can be located between the substrate22 and the side wall 23. The bonding layer 30 can be a gold layer. Thecap layer 31 can be a tin cap layer. The cap forms a hermetic sealaround the BAW resonators 24. Accordingly, an air cavity 25 can beincluded within the cap around the BAW resonators 24. In some instances,a BAW component can include 10 to 50 BAW resonators 24 enclosed within acap. The BAW resonators 24 can include one or more FBARs. Alternativelyor additionally, the BAW resonators 24 can include one or more SMRs. TheBAW resonators 24 can be included in one or more filters. The substrate21 can be a silicon substrate. The sidewalls 23 can include copper.

The BAW resonators 24 are on the substrate 22 and enclosed by the cap.The substrate 22 can be a silicon substrate. The conductive layer 27 inthe though substrate vias 26 can provide an electrical connection fromone or more of the BAW resonators 24 to elements on an opposing side ofthe substrate 22. As illustrated, the re-wiring layer 28 formed at block14 is over the substrate 22 and extends laterally from the thoughsubstrate vias 26. Accordingly, electrodes 29 can be formed over there-wiring layer 28 laterally from the though substrate vias 26. There-wiring layer 28 is on an opposite side of the substrate 22 than theBAW resonators 24. The electrodes 29 provide terminals for externalconnections to BAW components. With the re-wiring layer 28, theelectrodes 29 can be positioned at any suitable location of a BAWcomponent. The re-wiring layer 28 can provide shielding. The re-wiringlayer 28 can shield the BAW resonators 24 from external componentsand/or shield external components form the BAW resonators 24.

Referring back to FIG. 1, a buffer layer is formed over the substratesuch that streets are exposed at block 16. The buffer layer can beformed by way of a photolithographic process. Forming the buffer layercan include depositing a layer of buffer material, masking certain areasover the buffer material, and applying light to remove the buffermaterial over the streets. A surface of the substrate can be exposedalong the streets. The buffer layer can provide encapsulation of BAWcomponents on a side opposite the cap substrate. The buffer layer can beformed over the re-wiring layer formed at block 14.

FIG. 2B illustrates a cross section of BAW components that includes abuffer layer 32 formed at block 16 of the process 10. The buffer layer32 is over the substrate 22. The buffer layer 32 is on an opposite sideof the substrate 22 than the BAW resonators 24. A portion of the bufferlayer 32 is within through substrate vias 26. The buffer layer 32 isalso over portions of the re-wiring layer 28. As shown in FIG. 2B, thebuffer layer 32 is formed such that the electrodes 29 remain exposed.The buffer layer 32 includes a material that serves as a mask to resistetching while the substrate 22 is plasma diced. For instance, the bufferlayer 32 can be a material that is etched less than silicon whilesilicon is etched for a substrate 22 that is a silicon substrate.Typically, an etching rate of the buffer layer 32 is over 30 timesslower compared with an etching rate of silicon. Therefore, a typicalbuffer layer thickness is sufficient for plasma dicing the wafers. Thebuffer layer 32 can be a polyimide layer, a phenol resin layer such as aphenol resin layer with rubber filler, or any other suitable bufferlayer. The streets 34 facilitate dicing of the BAW components.

FIG. 2C illustrates a zoomed in view of a portion 35 of the BAWcomponents illustrated in FIG. 2B. As illustrated, the street 34 canhave a width D_(S). The width D_(S) is suitable for plasma dicing asillustrated. The width D_(S) of the street 34 can be in a range fromabout 10 microns to 20 microns, such as in a range from 10 microns to 15microns. As one example, the width D_(S) of the street 34 can be about15 microns. FIG. 2C also illustrates that a bonding layer 30 and a caplayer 31 can be included between the substrate 22 and the sidewall 23.

Referring back to FIG. 1, BAW components are plasma diced along theexposed streets at block 18. This singulates the BAW components. Inother words, the BAW components are separated from each other intoindividual BAW components by plasma dicing. The plasma dicing caninvolve dry etching through a substrate on which BAW resonators arelocated and through a cap substrate. There can be a hollow portionbetween the substrate and the cap substrate under the street (e.g., asshown in FIG. 2B) during this etching. As an example, the substrate andthe cap substrate can both be silicon substrates that are etched at arate of approximately 20 microns per minute. In this example, thesubstrate and the cap substrate can together be about 200 microns thickand it can take about 10 minutes to etch through about 200 microns ofsilicon. With plasma dicing, chipping of singulated BAW components canbe reduced relative to other dicing methods, such as blade dicing orlaser dicing. For plasma dicing, a photolithographic process can patternany suitable pattern for streets. In certain instances, this can resultin rounded corners for singulated BAW components. Such rounded cornerscan reduce the risk of the BAW component cracking and/or chipping tothereby increase reliability of the BAW component.

FIG. 2D illustrates a cross section of the BAW components after plasmadicing at block 18 of the process 10. Plasma dicing along streets canremove portions of the substrate 22 and the cap substrate 21 to therebyseparate individual BAW components. A plurality of singulated BAWcomponents 36 are shown in FIG. 2D. Tape 37 can hold the singulated BAWcomponents 36 together. The tape 37 can be laminated to the BAWcomponents prior to the plasma dicing.

FIG. 2E illustrates a zoomed in view of a portion 38 of singulated BAWcomponents 36 illustrated in FIG. 2D. As illustrated, a distance D_(E)from a sidewall 23 to an edge of the substrate 22 of a singulated BAWcomponent 36 is relatively small. Using a buffer layer as the mask forplasma dicing, a photolithography process can be used. Therefore, plasmadicing has a greater accuracy than other dicing methods, such as bladedicing or laser dicing with a mechanical system accuracy. For example,plasma dicing can be performed within an accuracy of +/−2 microns.However, in the case of blade dicing, mechanical accuracy is +/−10microns and there can be 5 to 10 microns of chipping. With the increasedaccuracy and reduced risk of chipping for plasma dicing, the distanceD_(E) from the sidewall 23 to the edge of the substrate 22 of thesingulated BAW component 36 can be reduced. The distance D_(E) from thesidewall 23 to the edge of the substrate 22 of the singulated BAWcomponent 36 can be less than 5 microns. The distance D_(E) can be lessthan 3 microns. As one example, the distance D_(E) can be about 2.5microns. The distance D_(E) is greater than zero as illustrated. In someinstances, the distance D_(E) can be in a range from 1 micron to 5microns, such as in a range from 1 microns to 3 microns. The sidewall 23and the edge of the substrate 22 can be substantially flush in asingulated BAW component in certain instances.

Accordingly, with plasma dicing, there can be less space betweenrespective sidewalls 23 of adjacent BAW components on a wafer. Adistance D_(SW) from sidewalls 23 of respective adjacent singulated BAWcomponents corresponds to the sum of the street width D_(S) and twicethe distance D_(E) in FIG. 2E. The distance D_(SW) can be in a rangefrom about 10 microns to 30 microns, for example. In some instances, thedistance D_(SW) can be in a range from about 10 microns to 20 microns.As an example, the street width D_(S) can be about 15 microns and thedistance D_(E) can be about 2.5 microns, which would make the distanceD_(SW) about 20 microns in the cross section illustrated in FIG. 2E.

FIG. 3A is a cross sectional diagram of a bulk acoustic wave component40 according to an embodiment. The BAW component 40 can be manufacturedby a process that includes plasma dicing. For instance, the bulkacoustic wave component 40 can correspond to a singulated BAW componentmanufactured by the process 10 of FIG. 1.

As shown in FIG. 3A, the distance D_(E) from a sidewall 23 to an edge ofthe substrate 22 of a singulated BAW component 36 can be relativelysmall as a result of plasma dicing. The distance D_(E) can be in any ofthe ranges and/or have any of the values disclosed herein, such asdescribed with reference to FIG. 2E. In illustrated the BAW component40, BAW resonators 24 are enclosed within a cap that include capsubstrate 21 and sidewalls 23. The BAW resonators 24 can form some orall of the resonators of one or more acoustic wave filters. There can beany suitable number of BAW resonators 24 enclosed within the cap of theBAW component 40. For instance, there can be 10 to 50 BAW resonators 24enclosed within the cap of the BAW component 40. The BAW resonators 24can be electrically connected to an electrode 29 by way of a conductivelayer 27 in a through substrate via 26 and a re-wiring layer 28. Thebuffer layer 32 extends over the re-wiring layer 28 and is includedwithin the through substrate via 26 in the BAW component 40.

FIG. 3B is a cross sectional diagram of a bulk acoustic wave component42 according to an embodiment. The BAW component 42 can be manufacturedby a process that includes plasma dicing. For instance, the bulkacoustic wave component 42 can correspond to a singulated BAW componentmanufactured by the process 10 of FIG. 1. The BAW component 42 is likethe BAW component 40 of FIG. 3A except that the BAW component 42includes a via 26 that is filled with conformal conductive layer 43instead of a conductive layer 27. The conformal conductive layer 43 canbe a copper layer, for example. The bulk acoustic wave component 42illustrates that the via 26 can be filled with a conformal layer 43.

One or more bulk acoustic wave resonators of a bulk acoustic wavecomponent including any suitable combination of features disclosedherein be included in a filter arranged to filter a radio frequencysignal in a fifth generation (5G) New Radio (NR) operating band withinFrequency Range 1 (FR1). A filter arranged to filter a radio frequencysignal in a 5G NR operating band can include one or more acoustic waveresonators of any bulk acoustic wave component disclosed herein. FR1 canbe from 410 megahertz (MHz) to 7.125 gigahertz (GHz), for example, asspecified in a current 5G NR specification. One or more bulk acousticwave resonators of a bulk acoustic wave component in accordance with anysuitable principles and advantages disclosed herein can be included in afilter arranged to filter a radio frequency signal in a fourthgeneration (4G) Long Term Evolution (LTE) operating band and/or in afilter with a passband that spans at least one 4G LTE operating band andat least one 5G NR operating band.

FIG. 4 is a schematic diagram of a transmit filter 45 that includes bulkacoustic wave resonators of a bulk acoustic wave component according toan embodiment. The transmit filter 45 can be a band pass filter. Theillustrated transmit filter 45 is arranged to filter a radio frequencysignal received at a transmit port TX and provide a filtered outputsignal to an antenna port ANT. The transmit filter 45 includes seriesBAW resonators TS1, TS2, TS3, TS4, TS5, TS6, and TS7, shunt BAWresonators TP1, TP2, TP3, TP4, and TP5, series input inductor L1, andshunt inductor L2. Some or all of the BAW resonators TS1 to TS7 and/orTP1 to TP5 can be included in a BAW component in accordance with anysuitable principles and advantages disclosed herein. For instance, theBAW component 40 of FIG. 3A or the BAW component 42 of FIG. 3B caninclude all of the BAW resonators of the transmit filter 45. In certaininstances, a BAW component in accordance with any suitable principlesand advantages disclosed herein can include BAW resonators of two ormore acoustic wave filters. Any suitable number of series BAW resonatorsand shunt BAW resonators can be included in a transmit filter 45.

FIG. 5 is a schematic diagram of a receive filter 50 that includes bulkacoustic wave resonators of a bulk acoustic wave component according toan embodiment. The receive filter 50 can be a band pass filter. Theillustrated receive filter 50 is arranged to filter a radio frequencysignal received at an antenna port ANT and provide a filtered outputsignal to a receive port RX. The receive filter 50 includes series BAWresonators RS1, RS2, RS3, RS4, RS5, RS6, RS7, and RS7, shunt BAWresonators RP1, RP2, RP3, RP4, and RP5, and RP6, shunt inductor L2, andseries output inductor L3. Some or all of the BAW resonators RS1 to RS8and/or RP1 to RP6 can be included in a BAW component in accordance withany suitable principles and advantages disclosed herein. For instance,the BAW component 40 of FIG. 3A or the BAW component 42 of FIG. 3B caninclude all of the BAW resonators of the receive filter 50. Any suitablenumber of series BAW resonators and shunt BAW resonators can be includedin a receive filter 50.

FIG. 6 is a schematic diagram of a radio frequency system 60 thatincludes a bulk acoustic wave component according to an embodiment. Asillustrated, the radio frequency system 60 includes an antenna 62, anantenna switch 64, multiplexers 65 and 66, filters 67 and 68, poweramplifiers 70, 72, and 74, and a select switch 73. The power amplifiers70, 72, and 74 are each arranged to amplify a radio frequency signal.The select switch 73 can electrically connect an output of the poweramplifier 72 to a selected filter. One or more filters of themultiplexer 65 and/or the multiplexer 66 can include one or more BAWresonators of a BAW component in accordance with any suitable principlesand advantages discussed herein. In certain instances, a BAW componentcan include one or more filters of a multiplexer. Although themultiplexers illustrated in FIG. 6 include a quadplexer and a duplexer,one or more BAW resonators of a BAW component can be included in anyother suitable multiplexer, such as a triplexer, a hexaplexer, anoctoplexer, or the like. The antenna switch can selectively electricallyconnect one or more filters and/or one or more multiplexers to theantenna 62.

The BAW components discussed herein can be implemented in a variety ofpackaged modules. These BAW components can consume less area in packagedmodules than similar modules that are diced using laser dicing. Apackaged module configured to process a radio frequency signal can bereferred to as a radio frequency module. Some radio frequency modulesare front end modules. Radio frequency modules that include a BAWcomponent in accordance with any suitable principles and advantagesdisclosed herein can also include one or more radio frequency amplifiers(e.g., one or more power amplifiers and/or one or more low noiseamplifiers), one or more radio frequency switches, the like, or anysuitable combination thereof. Example packaged modules will now bediscussed in which any suitable principles and advantages of the BAWcomponents discussed herein can be implemented. FIGS. 7 and 8 areschematic block diagrams of illustrative packaged modules according tocertain embodiments. Any suitable combination of features of theseembodiments can be combined with each other.

FIG. 7 is a schematic diagram of a radio frequency module 75 thatincludes a bulk acoustic wave component 76 according to an embodiment.The illustrated radio frequency module 75 includes the BAW component 76and other circuitry 77. The BAW component 76 can include any suitablecombination of features of the BAW components disclosed herein. The BAWcomponent 76 can include a BAW die that includes BAW resonators.

The BAW component 76 shown in FIG. 7 includes a filter 78 and terminals79A and 79B. The filter 78 includes BAW resonators. The terminals 79Aand 78B can serve, for example, as an input contact and an outputcontact. The BAW component 76 and the other circuitry 77 are on a commonpackaging substrate 80 in FIG. 7. The package substrate 80 can be alaminate substrate. The terminals 79A and 79B can be electricallyconnected to contacts 81A and 81B, respectively, on the packagingsubstrate 80 by way of electrical connectors 82A and 82B, respectively.The electrical connectors 82A and 82B can be bumps or wire bonds, forexample. The other circuitry 77 can include any suitable additionalcircuitry. For example, the other circuitry can include one or morepower amplifiers, one or more radio frequency switches, one or moreadditional filters, one or more low noise amplifiers, the like, or anysuitable combination thereof. The radio frequency module 75 can includeone or more packaging structures to, for example, provide protectionand/or facilitate easier handling of the radio frequency module 75. Sucha packaging structure can include an overmold structure formed over thepackaging substrate 75. The overmold structure can encapsulate some orall of the components of the radio frequency module 75.

FIG. 8 is a schematic diagram of a radio frequency module 84 thatincludes a bulk acoustic wave component according to an embodiment. Asillustrated, the radio frequency module 84 includes duplexers 85A to 85Nthat include respective transmit filters 86A1 to 86N1 and respectivereceive filters 86A2 to 86N2, a power amplifier 87, a select switch 88,and an antenna switch 89. The radio frequency module 84 can include apackage that encloses the illustrated elements. The illustrated elementscan be disposed on a common packaging substrate 80. The packagingsubstrate can be a laminate substrate, for example.

The duplexers 85A to 85N can each include two acoustic wave filterscoupled to a common node. The two acoustic wave filters can be atransmit filter and a receive filter. As illustrated, the transmitfilter and the receive filter can each be band pass filters arranged tofilter a radio frequency signal. One or more of the transmit filters86A1 to 86N1 can include one or more BAW resonators of a BAW componentin accordance with any suitable principles and advantages disclosedherein. Similarly, one or more of the receive filters 86A2 to 86N2 caninclude one or more BAW resonators of a BAW component in accordance withany suitable principles and advantages disclosed herein. Although FIG. 8illustrates duplexers, any suitable principles and advantages disclosedherein can be implemented in other multiplexers (e.g., quadplexers,hexaplexers, octoplexers, etc.) and/or in switch-plexers.

The power amplifier 87 can amplify a radio frequency signal. Theillustrated switch 88 is a multi-throw radio frequency switch. Theswitch 88 can electrically couple an output of the power amplifier 87 toa selected transmit filter of the transmit filters 86A1 to 86N1. In someinstances, the switch 88 can electrically connect the output of thepower amplifier 87 to more than one of the transmit filters 86A1 to86N1. The antenna switch 89 can selectively couple a signal from one ormore of the duplexers 85A to 85N to an antenna port ANT. The duplexers85A to 85N can be associated with different frequency bands and/ordifferent modes of operation (e.g., different power modes, differentsignaling modes, etc.).

FIG. 9A is a schematic diagram of a wireless communication device 90that includes filters 93 in a radio frequency front end 92 according toan embodiment. The filters 93 can include BAW resonators of a BAWcomponent in accordance with any suitable principles and advantagesdiscussed herein. The wireless communication device 90 can be anysuitable wireless communication device. For instance, a wirelesscommunication device 90 can be a mobile phone, such as a smart phone. Asillustrated, the wireless communication device 90 includes an antenna91, an RF front end 92, a transceiver 94, a processor 95, a memory 96,and a user interface 97. The antenna 91 can transmit RF signals providedby the RF front end 92. Such RF signals can include carrier aggregationsignals.

The RF front end 92 can include one or more power amplifiers, one ormore low noise amplifiers, one or more RF switches, one or more receivefilters, one or more transmit filters, one or more duplex filters, oneor more multiplexers, one or more frequency multiplexing circuits, thelike, or any suitable combination thereof. The RF front end 92 cantransmit and receive RF signals associated with any suitablecommunication standards. The filters 93 can include BAW resonators of aBAW component that includes any suitable combination of featuresdiscussed with reference to any embodiments discussed above.

The transceiver 94 can provide RF signals to the RF front end 92 foramplification and/or other processing. The transceiver 94 can alsoprocess an RF signal provided by a low noise amplifier of the RF frontend 92. The transceiver 94 is in communication with the processor 95.The processor 95 can be a baseband processor. The processor 95 canprovide any suitable base band processing functions for the wirelesscommunication device 90. The memory 96 can be accessed by the processor95. The memory 96 can store any suitable data for the wirelesscommunication device 90. The user interface 97 can be any suitable userinterface, such as a display with touch screen capabilities.

FIG. 9B is a schematic diagram of a wireless communication device 100that includes filters 93 in a radio frequency front end 92 and a secondfilter 103 in a diversity receive module 102. The wireless communicationdevice 100 is like the wireless communication device 90 of FIG. 9A,except that the wireless communication device 100 also includesdiversity receive features. As illustrated in FIG. 9B, the wirelesscommunication device 100 includes a diversity antenna 101, a diversitymodule 102 configured to process signals received by the diversityantenna 101 and including filters 103, and a transceiver 104 incommunication with both the radio frequency front end 92 and thediversity receive module 102. The filters 103 can include BAW resonatorsof a BAW component that includes any suitable combination of featuresdiscussed with reference to any embodiments discussed above.

Any of the embodiments described above can be implemented in associationwith mobile devices such as cellular handsets. The principles andadvantages of the embodiments can be used for any systems or apparatus,such as any uplink cellular device, that could benefit from any of theembodiments described herein. The teachings herein are applicable to avariety of systems. Although this disclosure includes some exampleembodiments, the teachings described herein can be applied to a varietyof structures. Any of the principles and advantages discussed herein canbe implemented in association with RF circuits configured to processsignals having a frequency in a range from about 30 kilohertz (kHz) to300 GHz, such as a frequency in a range from about 450 MHz to 8.5 GHz.

Aspects of this disclosure can be implemented in various electronicdevices. Examples of the electronic devices can include, but are notlimited to, consumer electronic products, parts of the consumerelectronic products such as die and/or acoustic wave filter assembliesand/or packaged radio frequency modules, uplink wireless communicationdevices, wireless communication infrastructure, electronic testequipment, etc. Examples of the electronic devices can include, but arenot limited to, a mobile phone such as a smart phone, a wearablecomputing device such as a smart watch or an ear piece, a telephone, atelevision, a computer monitor, a computer, a modem, a hand-heldcomputer, a laptop computer, a tablet computer, a personal digitalassistant (PDA), a microwave, a refrigerator, an automobile, a stereosystem, a DVD player, a CD player, a digital music player such as an MP3player, a radio, a camcorder, a camera, a digital camera, a portablememory chip, a washer, a dryer, a washer/dryer, a copier, a facsimilemachine, a scanner, a multi-functional peripheral device, a wrist watch,a clock, etc. Further, the electronic devices can include unfinishedproducts.

Unless the context clearly requires otherwise, throughout thedescription and the claims, the words “comprise,” “comprising,”“include,” “including” and the like are to be construed in an inclusivesense, as opposed to an exclusive or exhaustive sense; that is to say,in the sense of “including, but not limited to.” The word “coupled”, asgenerally used herein, refers to two or more elements that may be eitherdirectly connected, or connected by way of one or more intermediateelements. Likewise, the word “connected”, as generally used herein,refers to two or more elements that may be either directly connected, orconnected by way of one or more intermediate elements. Additionally, thewords “herein,” “above,” “below,” and words of similar import, when usedin this application, shall refer to this application as a whole and notto any particular portions of this application. Where the contextpermits, words in the above Detailed Description using the singular orplural number may also include the plural or singular numberrespectively. The word “or” in reference to a list of two or more items,that word covers all of the following interpretations of the word: anyof the items in the list, all of the items in the list, and anycombination of the items in the list.

Moreover, conditional language used herein, such as, among others,“can,” “could,” “might,” “may,” “e.g.,” “for example,” “such as” and thelike, unless specifically stated otherwise, or otherwise understoodwithin the context as used, is generally intended to convey that certainembodiments include, while other embodiments do not include, certainfeatures, elements and/or states. Thus, such conditional language is notgenerally intended to imply that features, elements and/or states are inany way required for one or more embodiments.

While certain embodiments have been described, these embodiments havebeen presented by way of example only, and are not intended to limit thescope of the disclosure. Indeed, the novel apparatus, methods, andsystems described herein may be embodied in a variety of other forms;furthermore, various omissions, substitutions and changes in the form ofthe methods and systems described herein may be made without departingfrom the spirit of the disclosure. For example, while blocks arepresented in a given arrangement, alternative embodiments may performsimilar functionalities with different components and/or circuittopologies, and some blocks may be deleted, moved, added, subdivided,combined, and/or modified. Each of these blocks may be implemented in avariety of different ways. Any suitable combination of the elements andacts of the various embodiments described above can be combined toprovide further embodiments. The accompanying claims and theirequivalents are intended to cover such forms or modifications as wouldfall within the scope and spirit of the disclosure.

What is claimed is:
 1. A method of manufacturing singulated bulkacoustic wave components, the method comprising: forming a buffer layerover a substrate of an array of bulk acoustic wave components so as toform exposed streets between individual bulk acoustic wave components,the substrate being a silicon substrate; and plasma dicing the bulkacoustic wave components along the exposed streets to thereby singulatethe bulk acoustic wave components, the buffer layer having an etchingrate that is at least 30 times slower than an etching of silicon duringthe plasma dicing.
 2. The method of claim 1 wherein each of thesingulated bulk acoustic wave components includes a bulk acoustic waveresonator and a cap enclosing the bulk acoustic wave resonator, and thecap includes a sidewall that is 5 microns or less from an edge of thesubstrate of the respective singulated bulk acoustic wave component. 3.The method of claim 2 wherein the sidewall is at least 1 micron from theedge of the respective singulated bulk acoustic wave component.
 4. Themethod of claim 1 wherein the plasma dicing includes etching throughboth the substrate and a cap substrate, a bulk acoustic wave componentof the bulk acoustic wave components including a bulk acoustic waveresonator located over the substrate and under the cap substrate.
 5. Themethod of claim 4 wherein the substrate and the cap substrate aresilicon substrates.
 6. The method of claim 1 further comprising forminga conductor over the substrate, the conductor extending laterally from avia that extends through the substrate, and the conductor beingelectrically connected to a conductive layer in the via.
 7. The methodof claim 1 the forming the buffer layer includes forming the exposedstreets by way of a photolithographic process.
 8. The method of claim 1wherein the bulk acoustic wave components each include a film bulkacoustic wave resonator.
 9. A method of manufacturing singulated bulkacoustic wave components, the method comprising: forming a buffer layerover a substrate of an array of bulk acoustic wave components so as toform exposed streets between individual bulk acoustic wave components;and plasma dicing the bulk acoustic wave components along the exposedstreets to thereby singulate the bulk acoustic wave components, each ofthe singulated bulk acoustic wave components including a bulk acousticwave resonator and a cap enclosing the bulk acoustic wave resonator, andthe cap including a sidewall that includes copper and is 5 microns orless from an edge of the substrate of the respective singulated bulkacoustic wave component.
 10. The method of claim 9 wherein the substrateis a silicon substrate.
 11. The method of claim 10 wherein the bufferlayer is a material that etches at least 30 times slower than siliconduring the plasma dicing.
 12. A method of manufacturing singulated bulkacoustic wave components, the method comprising: forming a conductorover a substrate of an array of bulk acoustic wave components, theconductor extending laterally from a via that extends through thesubstrate, and the conductor being electrically connected to aconductive layer in the via; forming a buffer layer over the substrateso as to form exposed streets between individual bulk acoustic wavecomponents and such that the buffer layer is over at least a portion ofthe conductor; and plasma dicing the bulk acoustic wave components alongthe exposed streets to thereby singulate the bulk acoustic wavecomponents.
 13. A method of manufacturing singulated bulk acoustic wavecomponents, the method comprising: forming a conductor over a substrateof an array of bulk acoustic wave components, the conductor extendinglaterally from a via that extends through the substrate, and theconductor being electrically connected to a conductive layer in the via;forming solder over the conductor such that the solder isnon-overlapping with the via; forming a buffer layer over the substrateso as to form exposed streets between individual bulk acoustic wavecomponents; and plasma dicing the bulk acoustic wave components alongthe exposed streets to thereby singulate the bulk acoustic wavecomponents.
 14. A method of manufacturing bulk acoustic wave components,the method comprising: providing a first wafer bonded with a secondwafer, the first wafer having bulk acoustic resonators thereon, and thesecond wafer being over and spaced apart from the bulk acousticresonators; forming a buffer layer on a side of the first wafer that isopposite to the bulk acoustic wave resonators such that streets areexposed; and plasma dicing through the first wafer and the second waferalong the exposed streets to form singulated bulk acoustic wavecomponents, the buffer layer having an etching rate that is at least 30times slower than an etching rate of silicon during the plasma dicing.15. The method of claim 14 wherein the first wafer and the second waferare silicon wafers.
 16. The method of claim 14 wherein each of thesingulated bulk acoustic wave components includes a bulk acoustic waveresonator of the bulk acoustic wave resonators and a cap enclosing thebulk acoustic wave resonator, the cap including a sidewall.
 17. Themethod of claim 16 wherein the sidewall is in a range from 1 micron to 5microns away from an edge of a substrate of the respective singulatedbulk acoustic wave component, the substrate corresponding to a portionof the first wafer prior to plasma dicing.
 18. A method of manufacturingbulk acoustic wave components, the method comprising: forming a bufferlayer over a silicon substrate of bulk acoustic wave components suchthat streets are exposed, the buffer including a resin; and plasmadicing the bulk acoustic wave components along the exposed streets tothereby singulate the bulk acoustic wave components, the singulated bulkacoustic wave components each including a bulk acoustic wave resonatorand a cap enclosing the bulk acoustic wave resonator, the cap includinga silicon cap substrate and a sidewall that includes copper and isspaced apart from an edge of the silicon substrate of the respectivesingulated bulk acoustic wave component by a distance in a range from 1micron to 5 microns.
 19. The method of claim 18 further comprisingforming a conductor over the silicon substrate, the conductor extendinglaterally from a via that extends through the silicon substrate, and theconductor being electrically connected to a conductive layer in the via.20. The method of claim 18 wherein the bulk acoustic wave resonator is afilm bulk acoustic wave resonator.